The National Transportation Safety Board has issued a letter urging reform in air traffic scheduling and training, USA Today reported Wednesday. The NTSB says it is common to schedule two eight-hour shifts in a 24-hour period, resulting in a lack of "normal sleep."

America's worst crash in five years occurred as the controller in charge worked with only two hours of sleep, the newspaper said. The controller working in August when a Comair Flight crashed in Lexington, Ky., said he did not see the jet taxi to a closed runway because he had turned away to complete paperwork.

USA Today said the controller had slept for two hours the previous afternoon, then returned to work at 11:30 p.m. for a second eight-hour shift.

The NTSB says the Federal Aviation Administration gives inadequate consideration to the impact of scheduling on fatigue and performance.